What is more portable? echo -e or using printf?

Question

I'm currently writing a bash testing framework, which requires to be as portable as possible.

So, at one point, I had to print a leading newline followed by some text which contains several expanded variables. This is the solution I've used.

echo -e "\n$number_of_specs ${units}, $number_of_specs_failed failed"

This seems okay but I'm not sure how portable that is compared to printing out the line using e.g. printf?

Any ideas or hints where I could find some references?

Answer 1

printf is more portable. It should always be preferred over echo -e. If targeting bash/zsh/ksh specifically, echo $'...' is also ok. If targeting zsh or ksh specifically, print is ok.

• http://cfajohnson.com/shell/cus-faq.html#Q0b
• http://www.in-ulm.de/~mascheck/various/echo+printf/
• http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html#tag_20_37_16

POSIX (last link) also discusses echo -n problems, which should also be avoided. Basically, never use options to echo, and for portability, use printf.)

Answer 2

The most portable (in terms of portability to ancient systems without printf) solution for leading newlines is obviously

echo
echo "$number_of_specs ${units}, $number_of_specs_failed failed"